Spark plug



W. E?. @@Lw EE AL SPARK PLUG NW10, 1925q 1561355 JNVENToRs WR ohon,

A TTORNE Y.

Patented Nov. 10, 1925.

UNITED STATES WILLIAM R. POLSON AND WILLIAM GRANT, OF BRUNEAU, IDAHO.

SPARK PLUG.

Application filed June 2D, 19244 Serial No. 721,287.

To all whom it may concern.'

Be it known that we, WILLIAM R. PoLsoN and vVViLLIAM GRANT, citizens of the United States, residing at Bruneau, in the county of Owyhee and State of Idaho, have invented certain new and useful Improvements in Spark Plugs, of which the following is a specification.

This invention relates to sparking devices for use in connection with internal combustion engines and relates particularly7 to y spark plugs.

The primary object of this device is the provision, in a manner as hereinafter set forth, of a spark plug so constructed that a plurality of sparking points are provided in order that a spark will always be had in the cylinder should the regular points of the primary and ground electrodes become carbonized and useless.

The invention contemplates the provision of a plug having a shell of ordinary construction and having a porcelain body within the shell having a constricted substan tially elongated lower portion and having the main electrode, running through the porcelain, broken and the ends thereof turned outwardly to protrude from the side of the elongated lower portion providing the first sparking points. The lower end of the electrode extends from the terminal portion of the porcelain, in the usual manner, to form a spark gap with a ground electrode extending inwardly from the shell of the plug.

The final object of this invention is the provision, in a manner as hereinafter set forth, of a spark plug of simple construction, of few parts, strong, and inexpensive t0 manufacture.

The invention will be best understood from a consideration of the following detailed description taken in connection with the accompanying drawings forming part of this specification, with the understanding that the invention is not confined to any strict conformity with the showing of the drawings, but may be changed and modified so long as such changes and modifications mark no material departure from the salient features of the invention as expressed in the appended claim.

In the drawing:

Figure 1 is a side elevation of a spark plug constructed in accordance with this invention. l

Figure 2 is a modification showing the provision of a plurality of sparking points.

Referring to the drawing in detail, numeral 1 indicates the body of the shell of the plug, the lower portion 2 thereof being peripherally threaded as at 3, as is the usual construction, for insertion into the aperture in an engine cylinder. The shell 1 has the usual longitudinally extending bore 4 therethrough, the upper portion 5 being of greater diameter than the lower portion and inte-- riorly threaded at its upper end as at 6 to take the threaded lower portion 7 of the gland or packing nut 8.

The body of the insulating portion used in conjunction with this -device is indicated at 9, which body has formed thereabout at the lower portion thereof the enlarged girdle 10 which is adapted to position in the enlarged portion 5 of the passage 4 and is held therefrom by the annular washer 11 at the lower portion and has the washer 12 upon the upper shoulder against which the lower edge of the collar 7 bears. This collar 7 as shown fits snugly about the body por* tion 9. The upper portion of the body is extended a substantial distance above the plug as indicated at 13 and the lower portion of the body has depending therefrom the substantially elongated cylindrical portion 14 which is of materially less diameter than the body portion as shown and is freely suspended in the recess or central bore 4 of the shell.

Extending through the center of the body of insulation and the upper and lower portions 13 and 14 thereof, is a two part primary electrode 15 and 15 which, as shown, at its lower portion, xtends substantially half-way the length of the portion 14 of the insulation and is there bent at right angles as at 16 and projected through the side of the lower portion 14 as shown and there has the terminal ends bent downwardly as at 17 parallel with the side of the terminal portion 14. The terminal end of the lower portion 14 has embedded therein the angled lower portion 15 which comprises a vertical portion 18 which projects from the free end of the portion 14 as shown and is in alignment with the main portion of the electrode 15, and the upper end is formed at right angles as at 19 to extend through the side of the portion 14 in alignment with the angled extension 16 of the main electrode and the outer or free end of this angled portion 19 is bent upwardly at right angles as at 20 in such a manner that the end thereof is adjacent but spaced from and in alignment with the downturned portion 17. A ground electrode 2l in the forni ot a right angled ineinber, is provided, having one leg einheddcd in the wall of the shell as shownand having the other` leg extended outwardly and spaced lroin the side of the depending terniinal end 1S ot the lower portion l5.

ln YFigure ot the drawing, there is shown a inodiiication of the structure shown in F igure l, provision being inade here for the ormation et a plurality 0i spark gaps before the iin-al spark or sparking point is reached. The lower portion ot the porcelain has embedded therein the horizontally positioned shank of a plurality of l"lshaped ineinbers 23. "l`he heads of these T-shaped ineinbers, iinlicated at 2l, are in alignment as shown and are slightly spaced one 'troni the other and :further are positioned between the points il' and 2O as shown. The oonstrnclion in this iforin the saineas in lligure las can be clearly seen, with the exception that the points l? and 2O are spaced a sulicient distance apart to allow tor the insertion therebetween ot the aligned heads 2l of the T-shaped nienibers 23. t will thus be seen that three spark lraps 25 are provided before the linal spari; gap is reached, thus giving a series or" sparks in the cylinder and, it' one ol the points becomes fouled the other points will continue to lire.

It is ot course understood that the device is not limited to the use ot' two ot these T- shaped ineinbers to provide three extra sparking gaps, but as inany ot' the ineniliiers may be used as is desired.

lVhen in use, if the spaced ends of the por tions 18 and 21 become carbonized to such an extent that a spark is no longer formed therebetween, the points 17', 20, 25 positioned at the side of the portion 14: will con tinue to spark, thus carrying on the action oi the cylinder, and in view ol the tact that these points are shielded within the shell bore Ll, it is less likely that they will get out ci' commission. t

leroni lthe Jioregoing description, it may be seen that an improved spark plug is provided, which has the advantage ot inore than one sparkn'ig point thus preventing failure et the cylinder due to the carbonization o'i' the lower ot' the points.

llaving thus described our invention what we claiin is:

` spark plug comprising, a shell, a body or isolation therein having the lower portion termed to provide an elongated cylindrical body ot relatively sinall diainecer and wholly within said shell, an electrode within said body lorn'ied into an upper and a lower portion, the lower end of the upper portion being bent at right angles to extend ihrongh and beyond the side of said elongated body and the upper end of the lower portion being bent at right angles to extend through an beyond the side ofthe body parallel with the iirst mentioned bent portion, the outer ends of said bent portion being in spaced relation to provide sparking points, and a ground electrode spacedV troni the lower end of said lower portion to provide a second sparking point. I

In testimony whereof, we alli): our signatures hereto.

WILLIAM R. POLSON. VVILLTAM GRANT. 

